Authentication

From reading the api docs, I couldn't see any way to authenticate with an email address and a password, it seems you have to use the unique userid, is this correct? For my app I was hoping to be able to prompt the user for their email address and password to authenticate.

Yes, you can lookup the unique id from the email/password by using the GetUserID method. Once you get the unique ID for the user, you should cache it and throw away the email/password information. This is safer for the user and also because the unique ID won't change, whereas the email or password may change.